Design of Life Extending Controls Using Nonlinear Parameter Optimization

This report presents the conceptual development of a life extending control system where the objective is to achieve high performance and structural durability of the plant. A life extending controller is designed for a reusable rocket engine via damage mitigation in both the fuel and oxidizer turbines while achieving high performance for transient responses of the combustion chamber pressure and the O2/H2 mixture ratio. This design approach makes use of a combination of linear and nonlinear controller synthesis techniques and also allows adaptation of the life extending controller module to augment a conventional performance controller of a rocket engine. The nonlinear aspect of the design is achieved using nonlinear parameter optimization of a prescribed control structure

The Economics of Wind Power: Destabilizing an Electricity Grid with Renewable Power

In this paper, we examine the impact policy choices, including a carbon tax, on the optimal allocation of power across different generation sources and on future investments in generating facilities. The focus in on the Alberta power grid as it is heavily dependent on fossil fuels and has only limited ties to other power grids, although the model could be extended to a larger and even multiple grids. Results indicate that, as wind penetrates the extant generating mix characterizing the grid, cost savings and emission reductions do not decline linearly, but at a decreasing rate. However, if flexibility is allowed then, as the carbon tax increases to $40 per tCO2 or above, existing coal plants start to be replaced by newly constructed wind farms and natural gas plants. If coal can be completely eliminated from the energy mix and replaced by natural gas and wind, substantial savings of 31.03 Mt CO2 (58$170/tCO2. The associated high capital costs of new generating facilities may thus not be an ideal use of funds for addressing climate change.Economics of wind power, grid system modeling, operations research, carbon taxes and coal power plants

Damage-Mitigating Control With Overload Injection: Experimental Validation of the Concept

1 The goal of damage-mitigating control is to enhance structural durability of mechanical systems (e.g., advanced aircraft, spacecraft, and power plants

Land use and energy nexus

In this research, the connection between land use and energy has been discussed from two points of view, i.e., the impacts of energy on land use and the impacts of land use on energy. This research identified several direct and indirect land use changes that occur by clearing vegetation, destroying top soils, and relocating human populations during the different stages of extraction, deposition, and transportation of fossil fuels and uranium ore; and during the establishment of renewable energy sources including wind turbines, hydro-power plants, and associated structures (highways, dams, culverts, tunnels, power station infrastructure, and energy transmission networks). Likewise, feedstock cultivation, processing, and transportation to biomass plants, as well as the production of biodiesel from municipal solid waste, require accessible land resources that further contribute to global land-use change. In the case of the impacts of land use on energy, mixed use development was found to be one of the most efficient approaches to achieve energy efficiency. Similarly, energy demand for motorized travel can also be reduced with the development of urban blocks and transit-oriented development. Furthermore, integrated combined heat and power systems, green space, and energy-supporting land use regulations were identified as energy savings strategies that may aid in achieving energy efficiency and ensuring sustainable development

Analysis and Mitigation of Power Quality Issues in Distributed Generation Systems Using Custom Power Devices

This paper discusses the power quality issues for distributed generation systems based on renewable energy sources, such as solar and wind energy. A thorough discussion about the power quality issues is conducted here. This paper starts with the power quality issues, followed by discussions of basic standards. A comprehensive study of power quality in power systems, including the systems with dc and renewable sources is done in this paper. Power quality monitoring techniques and possible solutions of the power quality issues for the power systems are elaborately studied. Then, we analyze the methods of mitigation of these problems using custom power devices, such as D-STATCOM, UPQC, UPS, TVSS, DVR, etc., for micro grid systems. For renewable energy systems, STATCOM can be a potential choice due to its several advantages, whereas spinning reserve can enhance the power quality in traditional systems. At Last, we study the power quality in dc systems. Simpler arrangement and higher reliability are two main advantages of the dc systems though it faces other power quality issues, such as instability and poor detection of faults

Damage Modeling and Life Extending Control of a Boiler-Turbine System

Abstract The main idea in life extending control (LEC), also known as damage mitigating control, is to redesign the controller in order to achieve a better tradeoff between structural durability and dynamic performance in a system. This task involves both damage dynamics modeling and LEC design. In this paper, we propose a new hierarchical LEC structure and apply it to a typical boiler system. There are two damage models in this structure: Model I is for on-line LEC; Model II is for on-line life prediction for critical components of the system. For model I, we incorporate the improved rainflow cycle counting method and a continuous-time damage modeling approach. While for model II, we choose a method based on the P-K theory which involves the mean stress effect. Finally, an optimal LEC scheme is proposed and simulation results show that the designed LEC substantially reduces the accumulated damage with a minimum loss of dynamic performance

Power Quality Enhancement in Wind Power Generation Integrated Distribution System using Fuzzy Logic Controlled CSC Based DVR

In this paper, a model of fuzzy logic controlled CSC based DVR system has been proposed with the objective of performing voltage regulation and harmonics reduction tasks simultaneously in a power distribution system. The distribution system is integrated with a standalone renewable energy source (RES) driven i.e. wind power generation system based on self excited induction generator (SEIG) supplying power to customers having a variety of loads. For power quality (PQ) enhancement in electric power distribution systems, the custom power devices (CPDs) designed with conventional controllers such as proportional- integral (PI), proportional-integral-derivative (PID) etc. are widely used. The objective of using CPD is to mitigate the PQ problems encountered in the power distribution system that includes short and long duration voltage variations, voltage imbalance, waveform distortions etc. Amongst the various types of CPDs, the dynamic voltage restorer (DVR) is considered to be one of the versatile CPD capable of solving multiple PQ problems. In most of the literatures, the DVR is found to be designed and implemented with voltage source converter (VSC) topology and not much research work has been reported on the application of current source converter (CSC) topology in DVR system over the last couple of decades. The proposed CSC based model has been simulated using MATLAB / Simulink for investigating its performance. The simulation results support the validity of the proposed model

A sustainable supply chain study of the Indian bioenergy sector

In India, more than one third of the population do not currently have access to modern energy services. Biomass to energy, known as bioenergy, has immense potential for addressing India’s energy poverty. Small scale decentralised bioenergy systems require low investment compared to other renewable technologies and have environmental and social benefits over fossil fuels. Though they have historically been promoted in India through favourable policies, many studies argue that the sector’s potential is underutilised due to sustainable supply chain barriers. Moreover, a significant research gap exists. This research addresses the gap by analysing the potential sustainable supply chain risks of decentralised small scale bioenergy projects. This was achieved through four research objectives, using various research methods along with multiple data collection techniques. Firstly, a conceptual framework was developed to identify and analyse these risks. The framework is founded on existing literature and gathered inputs from practitioners and experts. Following this, sustainability and supply chain issues within the sector were explored. Sustainability issues were collated into 27 objectives, and supply chain issues were categorised according to related processes. Finally, the framework was validated against an actual bioenergy development in Jodhpur, India. Applying the framework to the action research project had some significant impacts upon the project’s design. These include the development of water conservation arrangements, the insertion of auxiliary arrangements, measures to increase upstream supply chain resilience, and the development of a first aid action plan. More widely, the developed framework and identified issues will help practitioners to take necessary precautionary measures and address them quickly and cost effectively. The framework contributes to the bioenergy decision support system literature and the sustainable supply chain management field by incorporating risk analysis and introducing the concept of global and organisational sustainability in supply chains. The sustainability issues identified contribute to existing knowledge through the exploration of a small scale and developing country context. The analysis gives new insights into potential risks affecting the whole bioenergy supply chain

Supervisory Controller Validation For A Plug-In Parallel-Through-The-Road Hybrid Electric Vehicle By Software-In-The-Loop Testing

The goal of this research is to develop an operational supervisory controller for Wayne State University Hybrid Warriors\u27 hybrid electric vehicle architecture that can be transitioned easily to a hardware-in-the-loop testing environment for the 2011-2014 EcoCAR2 competition. It serves to demonstrate how model-based design, specifically software-in-the-loop testing, is effective for the initial steps in design, verification, and validation of a supervisory control strategy. Overall, the supervisory controller aims to meet all safety and functional requirements while reducing fuel consumption. The thesis starts by presenting a plug-in parallel-through-the-road architecture and its powertrain hardware components. Next, characteristics and capabilities of all significant powertrain components are explained along with the implementation of the vehicle plant model. Initial stages and preparations for the development of supervisory controller begin with applying the Design Failure Mode and Effects Analysis and identifying the functional vehicle requirements. Control strategies implemented within the supervisory controller are discussed in detail. Finally, results from the software-in-the-loop testing as well as safety critical fault mitigation are shown, to demonstrate the end product of a supervisory controller that has reached a high level of functionality and safety and therefore is ready for hardware-in-the-loop testing. Outlines are provided for extending the current work into next phases of hardware-in-the-loop testing, optimization using vehicle-in-the-loop results, and special applications such as cold-start

Multiple criteria decision analytical tools in assessing risk for green growth: the case of oil palm biomass in Malaysia

The heightening world issues arises from climate change and energy security has created a strong resonance for sustainable development. The utilisation of biomass resources is amongst one of the best strategies to counter carbon emission and energy security issues for waste-to-wealth. Over the last decade, the Malaysian government has shown its clear intent to be a front-runner in the green economy through its various green economy policies and programs, particularly focus on oil palm biomass industry. However, it is observed that the diffusion rate of the industry remains relatively slow as compared to other developing countries such as Thailand and Philippine. Literature, anecdotal evidence, and advocates as well as businesses have identified that one of the non-technical factors that contribute to this problem is financing difficulties. The complication of biomass value chain creation often engaged with high risk profile, capital intensive and long payback period which is unfavourable for financing based on conventional risk assessment. Thus, this research focusses on developing a full range risk assessment model in aiding the industry stakeholder to comprehend the risk profile in managing and mitigating risk in biomass value chain in Malaysia. Multiple decision analytical tools have been employed and developed to integrate non-quantitative factors in risk assessment and design risk mitigation strategy based on the strengths and preferences of different stakeholders’ role. The outputs can serve as policy recommendation to aid the authorities and policy makers to undertake policy reviews to effectively spur the biomass industry for green growth. Furthermore, financier and investor are recommended to utilise the information to enhance its financing decision, to offer financial products that customised the need of sustainable projects without losing great business opportunity. Last but not least, the framework also offers industry stakeholders a practical decision analysis and making tool to integrate preferences as well as quantitative information to mitigate risks before any losses in venturing into the biomass industry occurred